1. Technical Field
The present invention relates to an image-processing device and image-processing method, particularly to an image-processing device and image-processing method for correcting a face image.
2. Background Art
Conventionally, a technology of virtually performing makeup to a face image is well known in order to simulate what a face of a user looks like in application of cosmetics.
Patent Document 1 discloses a rouge makeup simulation technology of applying rouge to the captured face image of the user. Patent Document 2 discloses an eye makeup simulation technology of drawing an eye shadow and an eyeliner in the captured face image of the user. According to the technologies, the rouge or the eye shadow is applied to the face image of the user by superimposing the color of the rouge or eye shadow on the color of the face image of the user, so that the makeup can be performed according to a skin color of the user.    Patent Document 1: Japanese Unexamined Patent Publication No. 2000-279228 (Publication date: Oct. 10, 2000)    Patent Document 2: Japanese Unexamined Patent Publication No. 2000-285222 (Publication date: Oct. 13, 2000)
However, the following problems are generated in the conventional configuration.
In the technologies disclosed in Patent Documents 1 and 2, it is assumed that an optimum face image is prepared in order to perform the makeup simulation. Specifically, in the conventional technologies, it is assumed that an inexpressive, front face image, in which a periphery of the eye or cheek is not hidden behind another object but the whole surface of the face is evenly irradiated with light, is used. Therefore, for example, in a cosmetic store, a customer (a user) is seated while oriented toward a camera, and the customer prepares the image capturing by raising hairs or removing glasses. Then, under the lighting with which the customer is evenly irradiated, a sales person captures the optimum face image of the customer, and the inexpressive, front face image is input to a makeup simulator. The above procedure is repeated in the case of a failure in the makeup simulation. Therefore, it is necessary for the user to visit the cosmetic store in order to perform the makeup simulation, and it is necessary for the sales person to assist the user to capture the face image. For this reason, the user cannot easily try the makeup simulation. In the technologies disclosed in Patent Documents 1 and 2, the makeup simulation cannot be performed in an ordinary state, namely, in the state in which the hairs are not brushed up or the state in which the user wears the glasses.
For example, the technologies disclosed in Patent Documents 1 and 2 can be applied to a digital camera or a camera-equipped mobile phone to implement software performing the makeup to the captured face image. The technologies disclosed in Patent Documents 1 and 2 can also be applied as a makeup simulator operated in a personal computer or a server on the Internet. In this case, it is not necessary to make a request to the sales person to perform the makeup simulation.
However, in the technologies disclosed in Patent Documents 1 and 2, it is necessary for the user to prepare the ideal image for the makeup simulation, namely, the inexpressive, front face image, in which the periphery of the eye or cheek is not hidden behind another object and the whole surface of the face is evenly irradiated with the light. The following problems are generated in the case that the makeup simulation is performed by the conventional technology using a snap photograph (for example, a photograph in which the image of the user in the natural state is rapidly captured) taken with the digital camera or the camera-equipped mobile phone.
First, the snap photograph frequently includes face images, such as the face that does not face the front and the face with intentionally distortional expression, to which the makeup simulation is hardly performed in the first place. When the makeup simulation of the conventional technology is performed to such face images, intended correction cannot be performed, and unnatural result is generated.
Second, even if the orientation of the face taken in the snap photograph is close to the front, frequently part or the whole of the region to which the makeup should be performed is covered with another object such that the user wears the glass or such that the hairs covers a neighborhood of the eye. When the makeup simulation of the conventional technology is performed to such face images, the makeup is unfortunately performed to another object overlapping with the region to which the makeup should be performed.
Even if the glasses or hairs do not exist near the region to which the makeup should be performed, in the conventional technology, unfortunately the makeup is performed to an unintended spot such that the eye shadow invades in the eye in the case that a feature point of the face or an eye contour cannot correctly be extracted.
In the snap photograph, frequently the face is unevenly irradiated with the light, and frequently one of the right and left sides of the face is bright while the other is dark. When the makeup simulation of the conventional technology is performed to such face images, sometimes the face is unnaturally seen according to an applied makeup color (a color of the cosmetics). For example, sometimes a difference between the right and the left of the color (the color after the makeup) that is obtained by combining the color of the eye shadow (or the rouge) and the skin color through air-brush processing by the conventional technology is unnaturally seen compared with a difference of the original right and left skin colors. This problem becomes prominent in the case that the difference in brightness between the original right and left skin colors is hard to understand at first glance.
In view of the foregoing, an object of at least one embodiment of the present invention is to implement an image-processing device and an image-processing method, which can properly perform the makeup processing to the face image under a wide range of conditions.